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v@uiten gisten getint @ffice enATE-BAR.

@te tgehule wenn tu' it tigen tetttrt ttmt mit 'mating pnt ot tte tante.-

KNOW ALL MEN BY THESE PRESENTS: That-I, J. R. SMITH, of Salem, in the county of Essex, andCommonwealtb of Massachusetts, have invented certain new and useful Improvements in Grate-Bars; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification, in which- Figure 1 represents a topor plan view of one of my improved grate-bars.

Figure 2 represents a perspective view of the bar when turned bottom side up, and

Figure 8 represents a cross-section online A B, iig. I.

To enable those skilled in the art to which my invention belongs to make and u sethe same, I will proceed.A

to describe it more in detail.-

In the drawings, a series of double-curved ribs, A, united at each end by the anges BB, and at inter. mediate points by the lugs a, are Shown as constituting, in this instance, one bar; but n greater or less number of double-curved ribs A may be used in a single bar. To give greater strength to the bar, one or more of the ribs A i'n each bar are made lto project down below the ribs A, as 'seen at b; iig. 2. Y To fill up and make. the' side of the bar straight, a side piece is made, with a straight rib, E, andl end plunger, B B', and'two short, .curved ribs, C D, which, when applied as shown in the drawings, fit the side of thegrate-bar perfectly andv make the side straight, as clearly lindicated in .the drawings. The side piece will fiteither side of the bar, so

that vonly one pattern i s necessary for side'piece and one for grate-bar. By making the ribs-A with a. doublel curve, e d, the bar is not so liable to lie strained and injured by unequal'heating as it would be if 'the ribs were straight or even of a single curve. For instance, if one side-of the bar becomes heated first, the bar yields on the opposite side, and thus prevents the injury to the bar which would result from the sudden ezrpansion of one side without suitable provision for a corresponding bending ofthe baron the other side. By'the use. of one or more projections, b, which are also double curved, and the'connecting-piece a in combination with the doublei curved ribs A, a gratclbar 4is produced of great strength and durability, and yet one which is comparatively light.

Having described my improvements in grate-bars for furnaces, what I claim therein as new and'of my invention, and desire to secure by Letters Patent, is

1. The double-curved ribs A, in combination with the flanges B B and connections a, substantially as and for the purposes set forth.' y

2. rIhe combination, with the double-curved ribs A, of one or more projections, la, ang'es B B, and conncctions a, as and'for the purposes lset forth. l

3. The combination, with the side of the bar, of' the peculiarly-constructed filling-piece, composed of the parts lettered B B', C D, and E, for the purposcsstated. A

J. R. SMITH. Witnesses: v

C. SnwALL, HENRY HALE. 

